Method of treating neurodegenerative diseases

ABSTRACT

A method of treating a neurodegenerative disease which comprises administering 5-bromo-4-(4-morpholinyl)-2-pyrimidinamine or 4-(4-morpholinyl)-2-(1-piperazinyl)thieno[3,2-d]pyrimidine or a pharmaceutically acceptable salt thereof.

This is a divisional application of U.S. Ser. No. 07/672,066 filed Mar.18, 1991 now U.S. Pat. No. 5,075,305.

FIELD OF INVENTION

The present invention relates to the treatment of neurodegenerativediseases which comprises administering5-bromo-4-(4-morpholinyl)-2-pyrimidinamine or4-(4-morpholinyl)-2-(1-piperazinyl)thieno[3,2-d]-pyrimidine or apharmaceutically acceptable salt thereof.

BACKGROUND

Nerve growth factor (NGF) was first described by Buker (Anat. Rec.102:369-389, 1948) and Levi-Montalcini (J. Exp. Zool. 116:321-362, 1951)as an activity secreted by a mouse sarcoma tumor implanted in a chickembryo. Both sensory ganglion and sympathetic ganglion neurons grewneurites into the sarcoma, which also supported the growth of peripheralneurons in culture. The factor, purified to homogeneity from mousesubmandibular glands in 1956 by Levi Montalcini and Cohen (Proc. Natl.Acad. Sci. U.S.A. 42:571, 1956) consists of a complex (referred to as 7SNGF, from its sedimentation coefficient) comprised of three differentsubunits. NGF's neurotrophic activity resides entirely within theβ-subunit (hereafter referred to as NGF), a dimer consisting of twoequivalent monomers of approximately 13,000 dalton molecular weight.

A role for NGF as a neurotrophic factor in the peripheral nervous system(PNS) was rapidly established through both in vitro and in vivoexperiments (Levi-Montalcini and Angeletti, Physiol. Rev. 48:534-569,1968; Johnson, et al, Science 210:916-918, 1980). These studiesdemonstrated that sympathetic neurons of the PNS have an absoluterequirement for NGF for survival throughout life, while many sensoryneurons require NGF during certain periods of development. NGF issynthesized in the periphery by the nonneuronal target tissuesinnervated by the NGF-dependent neurons. Upon binding of NGF to itsreceptor, the NGF-receptor complex is internalized by the neuron andretrogradely transported back to the neuron cell body. NGF'sintracellular mechanism of action is not yet fully elucidated.

It was not until 1983 that NGF was detected in the central nervoussystem (CNS) (Ayer-LeLievre, et al, Medical Biology 61:296-304, 1983).This discovery was preceded by the demonstration that the cholinergicneurons of the basal forebrain are responsive to NGF (Schwab, et al,Brain Res 168:473-483, 1979). These neurons possess NGF receptors whichare indistinguishable from NGF receptors in the periphery. As in thePNS, NGF is synthesized by the target regions of the sensitive neurons,the hippocampus and the neocortex. NGF secreted by these target regionsbinds to its receptor and is internalized and transported back to thecholinergic cell bodies of the basal forebrain. The sensitivity of theseneurons is especially interesting since these neurons are consistentlydepleted in Alzheimer's Disease (AD). It is possible, therefore, that anagent which enhances nerve growth factor's activity may be useful intreatment of CNS degenerative diseases like AD as well as peripheralneuropathies or other PNS degenerative disorders.

The term fibroblast growth factor may now be used to refer to any one ofa family of peptide growth factors, but commonly refers to the bestcharacterized members of the family, basic fibroblast growth factor(bFGF) and acidic fibroblast growth factor (aFGF) (Klagsbrun, Prog.Growth Factor Res. 1:207-235). Both bFGF and aFGF are 154 amino acidpeptides of approximately 18,000 molecular weight. In addition, highermolecular weight forms of bFGF, but not aFGF, are found in some tissues.bFGF is found in most tissues, while aFGF is located primarily in thebrain. Neither bFGF nor aFGF contain signal peptide sequences,suggesting that these peptides are not secreted but are likelycell-associated and/or extracellular matrix proteins. Both peptides bindto heparin, a property that has been exploited for purification of FGFs.Both low and high affinity binding sites for the FGFs have beenidentified. The low affinity sites, found on cell surfaces and inextracellular matrix, are likely heparin-like molecules that serve toconcentrate FGF (Moscatelli, J. Cell Physiol. 131:123-130, 1987). Highaffinity receptors have been identified in many cell and tissue types,including nervous tissue, and some studies suggest that both bFGF andaFGF and possibly other members of the FGF family bind to the samereceptor (Neufeld and Gospodarowicz, J. Cell Physiol. 136:537-542, 1988;Basilico, et al, J. Cell Biochem. Suppl. 13b:78, 1989). Receptors foraFGF and bFGF have now been cloned from several species (Ruta, et al,Proc. Natl. Acad. Sci. U.S.A. 86:8722-8726, 1989; Lee, et al, Science245:57-60, 1989; Reid, et al, Proc. Natl. Acad. Sci. U.S.A.87:1596-1600, 1990). The receptor sequences contain putative tyrosinekinase domains and both aFGF and bFGF induce the phosphorylation of bothhigh and low molecular weight proteins in intact cells (Friesel, et al,Mol. Cell Biol. 9;1857-1865, 1989; Coughlin, et al. J. Biol. Chem.263:988-993, 1988), suggesting that this kinase activity represents themajor signal transduction pathway for the FGFs.

Both bFGF and aFGF have been implicated in differentiation anddevelopment in many tissues. In addition, the angiogenic properties ofboth peptides suggest that they may play a role in wound healing. Ofparticular interest is an increasing body of data suggesting that theFGFs function to promote neuronal differentiation and survival. BothbFGF and aFGF have been shown to induce neurite outgrowth in PC12 cells(Togari, et al, J. Neurosci. 5:307-316, 1985) and neurons (Lipton, etal, Proc. Natl. Acad. Sci. U.S.A. 85:2388-2392, 1988). In addition, bFGFhas been shown to imitate nerve growth factor's ability to rescue boththe cholinergic neurons of the basal forebrain and retinal ganglioncells following surgical transection of their project (Anderson, et al,Nature 332:360-361, 1988; Sievers, et al, Neurosci Letters 76:157-172,1987). Whether bFGF is acting directly on the neurons or indirectly viainteractions with glia is as yet unknown. Regardless, these studiessuggest that modulation of fibroblast growth factor activity may bebeneficial in neurodegenerative diseases.

Both 5-bromo-4-(4-morpholinyl)-2-pyrimidinamine and4-morpholino-2-piperazinothieno[3,2-d]pyrimidine and pharmaceuticallyacceptable salts thereof enhance the effects of nerve growth factor and4-morpholino-2-piperazinothieno[3,2-d]pyrimidine and pharmaceuticallyacceptable salts thereof enhance the effects of fibroblast growthfactor.

PRIOR ART DISCLOSURES

U.S. Pat. No. 3,763,156, issued Oct. 2, 1973, specifically teaches thesynthesis of 4-(4-morpholinyl)-2-(1-piperazinyl)thieno[3,2-d]-pyrimidineand its dihydrochloride salt in Example 1 thereof and teaches the use ofthe compound as an inhibitor of thrombocyte aggregation in blood. Thiscompound is generically disclosed in U.S. Pat. No. 3,475,429, issuedOct. 28, 11969 and U.S. Pat. No. 3,888,851, issued June 10, 1975. Theutility described for the '429 compounds is inhibition of plateletaggregation, and the utility described for the '851 compounds isinhibition of thrombocyte aggregation and adhesiveness. There arenumerous journal references which describe the platelet aggregationinhibition properties of this compound.

No reference was found to 5-bromo 4-(4-morpholinyl)-2-pyrimidinamine.

Compounds of the following general formula are disclosed as therapeuticagents for neurological diseases in the peripheral nervous system andthe central nervous system in European application 257,102: ##STR1##wherein R₁ can be hydrogen; R₄ is H, alkylC₁₋₄, or alkylthioC₁₋₄ ; andR₂ and R₃ can form a 5- to 7-membered heterocyclic ring having a sulfuratom therein.

Compounds of the following general formula are disclosed in Europeanapplication 305,184 as therapeutic agents for neurological diseaseshaving the effect of regenerating and repairing nerve cells: ##STR2##wherein X is an amino group including --NHalkylC₁₋₄ ; Y is an aminogroup or a mono- or di-substituted alkylC₁₋₄ amino group; and Z ismethyl substituted by a C₂₋₅ alkoxycarbonyl or lower alkoxycarbonylgroup; or Y and Z together form the group --N(R₅)--CO--CH₂ --.

Belgian 818,990 (Derwent 17421W) describes as antithrombotic agentscompounds of the following general formula ##STR3## wherein R₁ can bealkoxy, morpholino, thiomorpholino, or piperazino; R₂ can be morpholino;R₃ can be bromo; and R₄ can be hydrogen.

SUMMARY OF THE INVENTION

This invention provides a method of enhancing the effects of nervegrowth factor and a method of treating a neurodegenerative disease and,more particularly, a neurodegenerative disease selected from senilecognitive decline, Alzheimer's disease, myasthenia gravis, tardivedyskinesia, and dementia associated with Down's syndrome or Parkinson'sdisease by administering the compound5-bromo-4-(4-morpholinyl)-2-pyridinamine or the compound 4-(4morpholinyl)-2-(1-piperazinyl)thieno[3,2-d]-pyrimidine or apharmaceutically acceptable salt of said compounds.

This invention also provides a method of enhancing the effect offibroblast growth factor by administering 4-(4-morpholinyl)2-(1-piperazinyl)thieno[3,2-d]pyrimidine or a pharmaceuticallyacceptable salt thereof.

This invention also provides as a novel compound5-bromo-4-(4-morpholinyl)-2-pyrimidinamine and pharmaceuticallyacceptable salts thereof.

DETAILED DESCRIPTION OF INVENTION

The compound 5-bromo-4-(4-morpholinyl)-2-pyrimidinamine has thefollowing structure: ##STR4##

The compound 4-(4-morpholinyl)-2-(1-piperazinyl)thieno[3,2 d]pyrimidinehas the following structure: ##STR5##

The synthesis of the compound of Formula A is set forth herein asExample 1 The synthesis of the compound of Formula B is described inU.S. Pat. No. 3,763,156, issued Oct. 2, 1973, at column 9, lines 61 to75 and column 10, lines 1 to 26, which portion is incorporated herein byreference.

Pharmaceutically acceptable acid addition salts of the compounds ofFormulas A and B are illustratively hydrochloric, sulfuric, phosphoric,acetic, benzoic, citric, malonic, salicylic, malic, fumaric, oxalic,succinic, tartaric, lactic, gluconic, ascorbic, maleic, aspartic,benzenesulfonic, methane and ethanesulfonic, hydroxymethane- andhydroxyethanesulfonic. (See, for example, "Pharmaceutical Salts," J.Pharm. Sci. 66(1):1-19 (1977).

The compounds of Formulas A and B have been found to enhance theactivity of nerve growth factor. The compound of Formula B has beenfound to enhance the activity of fibroblast growth nerve factor. Theseactivities render the compounds of Formulas A and B useful in treatingneurodegenerative diseases. In particular, these compounds are useful intreating senile cognitive decline and Alzheimer's disease. The compoundsof Formulas A and B are also useful in treating myasthenia gravis,tardive dyskinesia, and dementia associated with Down's syndrome orParkinson's disease. The utility of the compounds of Formulas A and B intreating these neurodegenerative diseases is demonstrated using cultureof PC12 rat pheochromocytoma cells which have been shown to respond tonerve growth factor (NGF) (Tischler and Greene, Nature 258:341-342,1975). The PC12 rat pheochromocytoma cells respond to NGF bydifferentiating into sympathetic neuron-like cells. The cells ceasedividing, extend processes resembling neurites, and synthesize increasedlevels of neurotransmitters and neurotransmitter receptors. The testingprotocol used in evaluating the compounds of Formulas A and B exploitthe ability of NGF to increase the activity of the enzyme cholineacetyltransferase (ChAT), a major synthetic enzyme for acetylcholine(Greene and Rein, Nature 268:349-351, 1977). The test procedure is thefollowing.

PC12 cells were plated at a cell density of approximately 2.5×10⁵cells/well in rat tail collagen-coated 6-well cultivation plates havinga well surface area of 9.62 cm². Cells were incubated for 7 days in 1.5mL of a medium consisting of 85% RPMI 1640 supplemented with 10% horseserum and 5% fetal calf serum. The medium was replaced with fresh mediumthree times weekly. Test compounds were dissolved in H₂ O or ethanol ata 100× concentration, and 15 μL of the 100× solution upon plating thecells and at each subsequent feeding. All test dishes were also treatedwith NGF or bFGF. In addition, each assay contained wells of PC12 cellstreated with 10, 17.8, 32, 56, and 100 ng/mL of NGF.

Cells were harvested after 7 days in culture with the test compounds andNGF. The medium was aspirated and the cells rinsed with ice cold Puck'ssaline G, which was then also removed. The cells were then scraped,using a rubber policeman, in 40 μL of ice cold harvest buffer (20 mMTris-HCl pH 8.6, 0.2% Triton X-100). Ten microliters of the resultingcell lysate were assayed for protein content by the method of Markewell,et al (Methods Enzymol. 72:296-303, 1981) and another 10 μL aliquot wasassayed for ChAT activity using a modification of the method of Fonnum(Biochem. J. 115:465-472, 1969). Briefly, samples were incubated with anequal volume of reaction medium (100 mM NaH₂ PO₄ 0.6 M NaCl, 20 mM EDTA,200 mM choline bromide, 20 mM NaCN, 20 μM physostigmine, 1 mg/mL albuminand 0.12 mg/mL ¹⁴ C-acetyl coenzyme A, from New England Nuclear, 50mCi/mmol) for 30 minutes at 37° C. The reaction was stopped by theaddition of 3.5 mL of 10 mM Tris-HCl, pH 7.4, containing 200 μMacetylcholine bromide. Two milliliters of acetonitrile containing 5mg/mL of tetraphenylboron were then added to each sample, followed byextraction with 10 mL of a 20:1 mixture of toluene and Liquifluor (aproduct of New England Nuclear). Samples were then counted in a liquidscintillation counter. Activity was expressed as pMol of productformed/mg protein/minute.

The test results are set forth below where the activity is expressed asa percent increase over the neuortrophic factor alone.

    ______________________________________                                        Enhancement of NGF Effect with 4-(4-Morpholinyl)-2-(1-                        piperazinyl)thieno[3,2-d]pyrimidine                                           Choline Acetyltransferase Activity                                                                     % Increase                                           (pMol/min/mg protein)    Over NGF                                                               With 32 μM                                                                            With 32 μM                                    Without compound  of Compound                                                                              of Compound                                      ______________________________________                                        Control     3.83 ± 2.0                                                                           10.34 ± 1.6                                                                           269.97                                       NGF 10 ng/mL                                                                              8.45 ± 1.3                                                                           17.45 ± 5.0                                                                           206.51                                       NGF 17.8 ng/mL                                                                           12.23 ± 3.3                                                                           25.17 ± 2.0                                                                           205.81                                       NGF 32 ng/mL                                                                             16.88 ± 4.6                                                                           34.08 ± 3.0                                                                           201.90                                       NGF 56 ng/mL                                                                             27.90 ± 6.2                                                                           44.02 ± 6.4                                                                           157.78                                       NGF 100 ng/mL                                                                            24.13 ± 4.0                                                                           42.10 ± 5.0                                                                           174.47                                       ______________________________________                                        Enhancement of bFGF Effect with 4-(4-Morpholinyl)-2-                          (1-piperazinyl)thieno[3,2-d]pyrimidine                                        Choline Acetyltransferase Activity                                                                     % Increase                                           (pMol/min/mg protein)    Over bFGF                                                              With 32 μM                                                                            With 32 μM                                    Without compound  of Compound                                                                              of Compound                                      ______________________________________                                        Control    3.83 ± 2.0                                                                            10.34 ± 1.6                                                                           269.97                                       bFGF 1 ng/mL                                                                             7.35 ± 1.0                                                                            15.24 ± 3.3                                                                           207.35                                       bFGF 3.2 ng/mL                                                                           10.13 ± 1.50                                                                          23.23 ± 0.7                                                                           229.32                                       bFGF 10 ng/mL                                                                            10.45 ± 2.60                                                                          22.18 ± 3.4                                                                           212.25                                       bFGF 32 ng/mL                                                                            12.47 ± 1.10                                                                          24.11 ± 1.7                                                                           193.34                                       bFGF 100 ng/mL                                                                           12.53 ± 0.40                                                                          29.67 ± 10                                                                            236.79                                       ______________________________________                                        Enhancement of NGF Effect with 5-Bromo-4-(4-                                  morpholinyl-2-pyrimidinamine                                                  Choline Acetyltransferase Activity                                                                      % Increase                                          (pMol/min/mg protein)     Over NGF                                            ______________________________________                                        NGF 17.8 ng/mL   30.18 ± 4.82                                               1 μM + NGF 17.8 ng/mL                                                                      36.51 ± 3.02                                                                            120.97                                           3.2 μM + NGF 17.8 ng/mL                                                                    31.46 ± 9.13                                                                            104.24                                           10 μM + NGF 17.8 ng/mL                                                                     52.33 ± 9.87                                                                            173.39                                           32 μm + NGF 17.8 ng/mL                                                                      55.04 ± 11.29                                                                          182.37                                          100 μM + NGF 17.8 ng/mL                                                                     83.13 ± 5.35                                                                            175.45                                          ______________________________________                                    

The compounds of Formulas A and B or a pharmaceutically acceptable saltthereof would be administered to a patient in need of treatment eitherorally or parenterally. The amount of compound to be administered woulddepend in part on the age, weight, and general condition of the patient.Typically, a patient would be closely monitored by a physician who coulddetermine if the dosage amount or regimen of compound being administeredwas effective and well tolerated. The compounds of Formulas A and B orsalts thereof would be administered admixed with a pharmaceuticallyacceptable carrier. An effective unit dose of the compounds would befrom 0.083 to 1.67 mg/kg of body weight of the patient with a daily doseranging from 1.66 to 3.34 mg/kg of body weight of the patient.

For preparing pharmaceutical compositions from the compounds of thisinvention, inert, pharmaceutically acceptable carriers can be eithersolid or liquid. Solid form preparations include powders, tablets,dispersible granules, capsules, cachets, and suppositories.

A solid carrier can be one or more substances which may also act isdiluents, flavoring agents, solubilizers, lubricants, suspending agents,binders, or tablet disintegrating agents; it can also be anencapsulating material.

In powders, the carrier is a finely divided solid which is in a mixturewith the finely divided active component. In tablets, the activecompound is mixed with the carrier having the necessary bindingproperties in suitable proportions and compacted in the shape and sizedesired.

For preparing suppositories, a low-melting wax such as a mixture offatty acid glycerides and cocoa butter is first melted, and the activeingredient is dispersed therein by, for example, stirring. The moltenhomogeneous mixture is then poured into convenient sized molds andallowed to cool and solidify.

Powders and tablets preferably contain between about 5% to about 70% byweight of the active ingredient. Suitable carriers are magnesiumcarbonate, magnesium stearate, talc, lactose, sugar, pectin, dextrin,starch, tragacanth, methyl cellulose, sodium carboxymethyl cellulose, alow-melting wax, cocoa butter, and the like.

The term "preparation" is intended to include the formulation of theactive compound with encapsulating material as a carrier providing acapsule in which the active component (with or without other carriers)is surrounded by a carrier, which is thus in association with it. In asimilar manner, cachets are also included.

Tablets, powders, cachets, and capsules can be used as solid dosageforms suitable for oral administration.

Liquid form preparations include solutions suitable for oral orparenteral administration, or suspensions, and emulsions suitable fororal administration. Sterile water solutions of the active component orsterile solutions of the active component in solvents comprising water,ethanol, or propylene glycol may be mentioned as examples of liquidpreparations suitable for parenteral administration.

Sterile solutions for injection or infusion may be prepared bydissolving the active component in the desired solvent system, and thenpassing the resulting solution through a membrane filter to sterilize itor, alternatively, by dissolving the sterile compound in a previouslysterilized solvent under sterile conditions.

Aqueous solutions for oral administration can be prepared by dissolvingthe active compound in water and adding suitable flavorants, coloringagents, stabilizers, and thickening agents as desired. Aqueoussuspensions for oral use can be made by dispersing the finely dividedactive component in water together with a viscous material such asnatural or synthetic gums, resins, methyl cellulose, sodiumcarboxymethyl cellulose, and other suspending agents known to thepharmaceutical formulation art.

Preferably, the pharmaceutical preparation is in unit dosage form. Insuch form, the preparation is divided into unit doses containingappropriate quantities of the active component. The unit dosage form canbe a packaged preparation, the package containing discrete quantities ofthe preparation, for example, packeted tablets, capsules, and powders invials or ampoules. The unit dosage form can also be capsule, cachet, ortablet itself, or it can be the appropriate number of any of thesepackaged forms.

EXAMPLE 1 5-Bromo-4-(4-morpholinyl)-2-pyrimidinamine ##STR6##

Compound I is prepared from 5-bromouracil by standard procedures (D. M.Mulvey, et al, J. Heterocyclic Chem. 10(1):79-83 (1973)).

2.5 g (0.0109 mol) of 5 bromo-2,4-dichloropyrimidine (I) is admixed with100 mL of absolute ethanol. The resulting suspension is then vigorouslystirred, and while stirring 2.1 g (0.0241 mole) of morpholine is added,accompanied by cooling to maintain the mixture at 20° C. The mixture isthen stirred for 2 hours more at room temperature. The precipitate isthereafter separated by vacuum filtration and washed with water andethanol, and dried in vacuo to yield 2.0 g (66%) of white solid. Theproduct can be purified by recrystallization with absolute ethanol. 6.0g (0.0215 mol) of 5-bromo-2-chloro-4-morpholinopyrimidine (II) isdissolved in 120 mL methanol. The solution is saturated with gaseousammonia, sealed in a bomb, and heated at 45°-50° C. for 45 hours. Theammonium chloride salt is isolated by slurrying in methylene chlorideand filtration. The filtrate is concentrated, triturated with ethylacetate, filtered, and dried in vacuo to yield 2.64 g (47%) of anoff-white solid.

We claim:
 1. A method of treating a neurodegenerative disease in a patient in need thereof which comprises administering to said patient an effective amount of a compound selected from 5-bromo-4-(4-morpholinyl)-2-pyrimidinamine, 4-(4-morpholinyl)-2-(1-piperazinyl)thieno[3,2-d]pyrimidine or a pharmaceutically acceptable salt thereof.
 2. The method of claim 1 wherein the neurodegenerative disease is selected from senile cognitive decline, Alzheimer's disease, myasthenia gravis, tardive dyskinesia, and dementia associated with Down's syndrome or Parkinson's disease.
 3. The method of claim 2 wherein the compound is 5 bromo-4-(4-morpholinyl)-2-pyrimidinamine or a pharmaceutically acceptable salt thereof.
 4. The method of claim 2 wherein the compound is 4-(4-morpholinyl)-2-(1-piperazinyl)thieno[3,2-d]-pyrimidine or a pharmaceutically acceptable salt thereof.
 5. The method of claim 3 wherein the neurodegenerative disease is senile cognitive decline.
 6. The method of claim 3 wherein the neurodegenerative disease is Alzheimer's disease.
 7. The method of claim 4 wherein the neurodegenerative disease is senile cognitive decline.
 8. The method of claim 4 wherein the neurodegenerative disease is Alzheimer's disease.
 9. A method of enhancing the effect of fibroblast growth factor in a patient in need thereof which comprises administering to said patient an effective amount of 4-(4-morpholinyl)-2-(1-piperazinyl)thieno[3,2-d]pyrimidine or a pharmaceutically acceptable salt thereof. 